Electric switch



G. CAMERON ELECTRI SWITCH Nov. 6,1923. 1,413,010

'A Nov. 6v, 1923;

1,473,910n G. CAMERON ELECTRIC SWITCH ts-Sheet 2l 79 :5? a 74 70 55 v 4 f /07 Nov. 6 1923. Y 1,473,010

G. CAMERON ELECTRIC SWITCH 'Filed Feb. 27. 1918 v sheets-sneer. :s

51,94 www y! as; 'v

M www' Patented Nov. 6, 1923. i

viJNiTEn STATES GORDN CAMERON, 0F WOLLASTO'N, MASSACHUSETTS, ASSIGNOR TO SEARS y JR., OF BOSTON, MASSACHUSETTS. A

1,473,010 PATENT OFFICE.

B. connrr,`

ELECTRIC SWITCH.

Application led February 27, 1918.` Serial No. 219,379.

To all whom. t 'may concern:

Be it known that I, GORDON '(LminntiN, a subject of the King o1"- Great Brit-ain, and a resident of `Wollaston, county of Norfolk, and State of lVlassachusetts, have invented an improvement in Electric. Switches, of which the following is a specitcation.

My linvention relates to electric switches adapted 'for the control ot motors or other electric power consuming apparatus or devices, and has particular reference to that type or' switch in which the switch conH tacts are immersed in oil.

An object of my invention is thev design of a switch and enclosing case therefor in which the operating parts are completely enclosed, and thereby protected 'from external influences, and yet which may be readily and easily opened' for the inspection ot the switch mechanism.

A further object of my invention is the provision of means whereby the removal oic cover plate from the switch enclosingcase causes a movement ot the switch mechanism from a closed to an open position, thereby causing the switch mechanism to be dead or disconnected from the line and thereby harmless previous to any possible Contact therewith by an operator upon a move to adjust or repair the mechanism.

The` means by which l accomplish this object of my invention is the disposition of a member in engagement with cover plate and so arranged that when said cover plate is in position on the enclosing case, the member is moved from operative engagement with the switch mechanism, butfupon the removal of the cover plate from the switch enclosing case, said' member is permitted to be moved into engagement with the latch, or means restraining the switch in closed position, to cause the disengagement of the latch and the consequent unlocking of the switch members and their removal to open position.-

Another object of my invention is to provide means whereby all removable plates or covers of the enclosing case are locked against removal from said case by a prede?V termined cover plate in its covering posi-V tion on the case.

The means by which this object of' my ini locking engagement with a cover by its spring, but adapted to be moved and maintained into locking, engagement with the cover by the movement of said locking cover into, and the maintenance thereof in closed relation with the switch enclosing case.

yAnother object of my invention is the provision of aswitch whereby the operator is compelled to rapidly move the switch mecha` nism toward closed position in order to move insuch closed position and in which the switch is locked `out from such closed position upon an insufficiently rapid movement of the switch mechanism toward closed position.

The means by which I accomplish this ob\70 ject of my invention is the provision eta pivoted latch adapted to engage a projection on the switch handle when said' handle is in half-open position, but to be disengaged there-from during a sufficiently rapid move- 75 ment of said handle from full open position f toward closed position.

Another object of my invention is the con` struction of a switch. the component parts o't` which are formed from stamped or drawn sheet metal, whereby the expense of makina* the switches in quantities is relatively low. and' which parts are strong, substantial and durable in operation. y

Fig. 1 is an elevation, partly in section, of a switch embodying my invention.

vFig. 2 is a1 plan view of the switch with top cover removed.

Fig. 3 is a sectional view along the lines 3-3 of Fig. 2.

Fig. 4 is a section taken along lines 4-4 of l'. 4 y

Fig. 5 is a detail ofthe locking means for the oil receptacle.

Fig. 6 is a detailof the switch operating mechanism in open position.

Fig. 7 isa detail of the latch with cover removed. f

Fig. 8 is an enlarged plan view of the latch.

As here shown, the switch includes the supporting or base plate 10, upon whichV the switch mechanism is disposed. Said base plate 10 is of rectangular form and iserranged at the bottom of the rectangular case or enclosure 11, which is formed with a lower inturned edgeor bottom 12 to provide a support therefor, and to which said base is secured. Said case 11 is adapted to be fixed to a support by suitable supporting' means, not necessarily shown.

An oil receptacle 13, formed ot drawn metal and of cylindrical form, is secured to the nuclei' side of said case, and is adapted to be filled with oil to a depth suiiicient to effectively cover the switch contacts depending therein from the base 10. rlhe upper peripheral portion of said oil receptacle 13 is provided with tour reiiexed strips of sheet metal 14;, riveted or otherwise secured thereto. The reiiexed ends 15 are outwardly extended and at a slight anrjle with the axis ot' the oil can, thereby forming, in e1'- fect, portions ot screw threads. Said thread members 111 are adapted to be rotated or screwed into engagement with complementary members 16 secured to the inturned edged portion 12 ot the case 11, whereby the open end of the oil can. is forced and held securely into engagement with the base 10.

A pin 14', secured to the bottom 12 of the case 11, is disposed in the path ot movement of said thread portions 14 to limit the rotary movement of the oil container.

The top of.' said enclosure or case 11, in which is disposed the operating mechanism for the switch members, is formed of two portions, one oi? which, 17, is permanently Secured to the top of said case, and the other of which, 18, is detachably secured thereon. The permanently secured cover portion 17 is formed, at the terminal edge thereof intermediate the end walls of said enclosure, with an upturned edge 19. A strip 2O is riveted to the interior tace of said cover portion whereby to form a groove or slot therebetween and the upturned edge 19 in which the edge 21 ot the detachable cover portion 1S may be disposed when in position on the casing,r 11. Said cover portions are formed with downwardly bent edges to snugly engage the walls of the enclosure 11, and tbe more effectively to cover the top openingthereof. The interior surface ot the detachaliile cover portion 18 adj acent the wall of the enclosure or casing, is provided with resilient arm 22, formed with a slot or opening` 23 therein. and `an inwardly bent end portion.

A pin 241 is secured to the wall of the easH ing 11 and, in the closed position of the cover 18, is disposed in the opening 23 of said resilient arm thereby locking said cover'against unintentional removal from said case.

A button is arranged in the wall of the casing 11, one end of which engages the resilient arm 22, and the other end of which projects through the said wall and is adapted to be pressed inwardly to Hex said arm 22 sufficiently to enable the disengagement of the pin 24C with said arm, whereby that end of the cover portion 18 bearing said arm may be moved upward until the arm clears the top of the enclosure, whereupon the cover portion may be laterally moved from the enclosure and access to the interior thereof obtained.

That portion of the switch mechanism depending from the base 10 into the oil can or receptacle 13 is supported from the trames Q5 formed ot metal strips bent into substantially rectangular form and secured to the base 10, in spaced relation by rivets passed through the inturned. ends 26 thereof. insulating bars 27 and 2S are secured to said 'frames 25 in spaced relation by bolts or screws, 29, and form terminal boards or blocks to which the movable and station-- ary switch contacts and members are secured and from which connection is made to the line or other component parts ot the switch.

'."he ends of the terminal boards 2? and 23 are 'toi-ined to closely conform to the shape ot' the oil container lf3, whereby said blocks 2T and 2S form `guides aiding in the correct positioning` ot the container to the switch housing. Said blocks also vform means pre* venting' the container from being),` moved into contact with a switch or contact member'.

The stationary switch contacts include Contact strip 31. The lower ends ot said strips are bent at right angles to 'fo-rm contact portions 31 extended beneath said board 2T and said strips are secured to said board in spaced relation by means ot bolts 82.

The ends oi the contact portions 31 of the strips BO are provided with slotted auxiliary contacts which are adapted to be engaged by the. auxiliary contact members ot the movabe switch members. Said auxiliary contacts 33 are detachably secured to the Contact ends oit the strips; 30. and are formed with duplicate contact faces whereby` upon the erosion ot one tace, the contacts may be reversed to present a 'fresh engaging` or con tactini;` tace.

The upper ends of the. contact strips 30 project through apertures in insulating' bushings 311 arranged in the metal base 10. whereby said strips arel insulated :from said base,

and said strips terminate in binding1 m'eans,

as bolts 35, by which connection to the line or circuit to he controlled 'may be obtained.

The terminal block. 28 is arranged to support the movable switch members which are pi-voted to lugs secured to said block. Said lugs are formed with a back portion 3G, the edges oi which are flexed to form the side portions extended into the ears 37 to which the movable switch members are pivoted at 38. A recess is thereby formed between the back 36 of said lugs and the rel'lexed side portions thereof and conducting' strips 39 are dispo-sed therein and clamped between the back ot said lugs and the terminal blocks by means of bolts 40 thereby securing said strips Vand lugs securely to said block and also providing e'liicient electrical contact between said strips and, lugs.

rlfhe conducting strips, 39, above those portions thereof secured to the terminal board, are twisted at right angles thereto, and extend upwardly tl'irough bushings 4l in the base l0. rlhe upper and terminal portions thereof, projecting above the base'lO, have secured thereto, by means of bolts 42, conducting leads 48, which form terminals of the overload trip coils hereinafter to be described.

The movable switch members 44 are formed of fiat strips and are pivoted at 38 to said lugs depending' from the terminal block 8. The end portions of said switch members 44, which are pivoted to said lugs, are twisted. as shown, intor a plane at right angles to the major portion of the strip, whereby a large bearing surface. is obtained with said lugs. The other ends of said strips are -bent or relexedto form two substanti ally parallel portions 45 and 46, which form supports for the auxiliary switch cony taCts 47.

Auxiliary kcontacts 47 yare formed of cylindrical rods slidably disposed in the parallelportions 45 and 46 of said movable switch members 44, and coiled springs 48 are disposed thereon between said parallel portions. Pins 49 are arranged in said contacts and against which said springs act to extend said contacts in the direction of .the stationary contacts.

Because of said springs, the auxiliary contacts are adapted to make initial contact with the stationary contact strips at the detachable members 33, and thereafter to yieldingly engage said contacts upon continued movement ofthe movable switch members to permit the subsequent engagement of the main switch contacts.

Y The linal break between the stationary and movable contacts is also arranged to occur between said auxiliary contacts, and therefore said Contacts receive the destructive arc caused by said break or rupture of the circuit. As said contact rods 47 are inexpensive, they may be cheaply renewed when necessary.. j

Pig tails or flexible leads -50 are secured to the ends of said contact rods 46 by means. of screws 51 and the other ends of said leads are clamped between the switch arms 44 and the operating means for said arms.

The main Contact, or brush, members 52 are secured to the arms 44 intermediate the ends thereof, by bolts 53and are adapted to make contact with the contact portions 31 of the contact strips 30. Said brush vmembers are composed ofa plurality of flexible leaves, as is common practice.

Bar 54 of aninsulating material. such` as wood, for instance, is secured to all of said `ed at 65.

switch arms 44 intermediate the ends thereof by bolts 53, and forms means insulatingly connecting all of said switch arms for simultaneous movement. The bolts 53 serve to secure in fixed relation tothe switch arms 44, the brush members 52, the flexible leads 59 and the main conducting leads 55 which are clamped between-said bar 54 and the switch arms 44, the other ends of said latter leads being connected to the terminal board 28 by means of the bolts 40, and by means of which leads connection is made between the movable switch members and the Contact strips 39.

The ends of said bar 54 project beyond the end switch arms 44 and stirrupmembers 56, formed of sheet or strip material, are secured thereto by means of bolts 57. Said strips form means to which the switch operating mechanism is attached, and by means of which the movable switch members are controlled.

The switch operating mechanism includes the shaft 58, journalled in brackets or supports 59 upon the supporting base 10 within the enclosing case 11 and ext-ending substantially across the width of said case.

An arm 60 is secured to one end of said shaft 58, and has a roller 61 pivoted at 61 to the extremity thereof. Said roller is adapted to be engaged by the latch. hereinafter to be described to restrain the switch in closed position.

Said arm 60 is formedwith a lateral extension 62, the end 62 of which is bent at right angles with the extended portion to form a projection adaptedto be engaged by the switch operating handle to move the switch from open position into closed position.

A link 63 is pivoted at A64 to an intermediate part of arm 60, and said link extends through the base 10 to the stirrup 56 of the movable switch member, to which it is pivot-- The end of the operating` shaft 58, remotefrom said armk 60 is provided with an arm 66 arranged in a plane with said arm 60 and has a second link 63, corresponding to the lirst link 63, pivoted thereto at 67. The other end of said second link 63is pivoted to the` other stirrup. Said links 63 and arms 60 and 66 form means whereby a movement of the operating shaft 58 serves to move they movable switch member between open and closed positions. y

The operating shaft 58 extends through and beyond the arm 69 secured thereon and an operating handle 68 is loosely mounted thereon and restrained against removal therefrom by the Cotter pin 69.

The side face 70 of the operating handle is adapted to engage' the projection 62 of the arm 60 to thereby move said arm 60 in a direction toward switch closed position, and the arrangement is such as to permit tore oit the operating mechanism.

The operating handle 68 'is also lormed its extremity, with an inturned projection 71, which is adapted to engage a part oit the latch or switch locking` means to cause the disengagementthereof with the roller 6l ot the arm G0, to permit a movement oi tl c switch members to open circuit position.

The operating handle 68 projects through the base l0 and inturned edge l2 oit the enclosure ll. through a slot provided for that purpose, and a. hand engageable portion 72 is detachably seein-ed thereto. Said portion 72 of the handle is bent, as shown, to prevent contact ,or the hand with the oil receptacle 13 in the operation oit the switch.

By the provision 01; a iandlc ronstrncteil in two parts as shown, various 'forms of handle extremities may be provided to adapt the switch for shipper operation or 'tor connection with a rope, cable or link tor remote cont-rol.

A spring washer l2() is loosely arranged on the operating shaft 58 and between the ,iperatingr handle G8 and the arm 60 whereby said handle and arm are held in :ti'ictional engagement. By this means the handle may remain ina position to indicate the closed condition of the switch instead ot falling' back to a vertical position as it might otherwise do, and may also be moved toward the right. independently ot the switch mechanism to cause the tripping ot the switch.

Limit stops 79 are secured on base 10 underl the arm GO and (i6 and in the paths oit' movement thereof, and serve to limit the open circuit movement of the switch mec Lanism.

Means are provided whereby the operating handle must be moved toward switch closed position above a certain predetermined speed to arrive at that position, and to thereby move the switch members into closed position. Said means include a latch 73 disposed above the operating handle and pivoted to the wall of the enclosure ll at 74.

Said latch 73 is formed with a lower arcuate tace 75, which is adapted to be enlaaged by, or be in sliding contact with, a tooth or projection 76 struclt` from the metal composing the handle 68. The curve ci said face 75 is such that, in the passage ot the projection 76 there under, the latch is not moved.

Tho arcuate tace 75 o't the latch .is formed, intermediate its length, with a semi-circular depression or not-ch 77. One edge ot the arcuate or cam face 75 has the beveled portion 78. The tip of the tooth or projection "Y6 oi the operating handle has a semi-circular form and is normally adapted to be engaged by the notch 77 of the latch.

In a movement of the switch handle to close the switch, the handle is moved rapidly toward the lett, or switch closed position from the eXtreme right or open position. The toothed projection 76 ot the handle in such movement moves onder the latch 78 without causing a movement thereoit nntil it arrives attl i n or noti' H' The latch being now imsnppo ward movement, begins to tall. nient ot the handle is sutlicicn projection 7S will more across 7? heitere the latch ialls suiciently to efiectively engage the projection, and the handle, therefore, is unrestrained in its movement into closed position. it the speed ot operation oit the handle, however` is below a certain predetermi ed vaine, the latch will tall sufficiently during the passage ot the projection 76 across the notch 7"? of the latch, to eftectiif'cly engage the tooth and thereby re "rain the handle, and consequently the sn h meclianisnii. against further movement toward closed position.

A. latch 8O is provided whereby the switch normally is restrained in closed position. Said latch is itormed, intern'iediate its length, with a boss through which a pin 80 extends, and upon which said latch is pivotally mounted. Said pin SO secured to the wall ot the casing ll, and to a 'frame 8l secured to said casing and said latch is disposed therebetween.

The latch is formed with an end portion having` a semi-circular roller engaging face 82, adapted to receive the roller 6l. carried y the arm (SO oi the switch mechanism to .normally restrain said mechanism in closed position. That part ot the latch beneath the circular recess, 82 is re'tlered to form an inclined portion 83 at right angles to the latch. Said inclined extension 83 is adapted to be engaged by the projection 7l formed on the handle in a movement of said handle toward nllopen position oit the handle to move said latch from the switch mechanism and permit the movement of the switch members to open position.

A spring 8e, coiled about the pin 80 tends to maintain the l ch in normal raised nd roller position.

The latch extends beyond its pivoted connection with pin SO', and said extension is formed with a A.tlantna 85 disposed thereon at right angles to the plane oit the latch. A spring 86 is coiled about the pin 80', and has one end 87 thereof extended under said flange. Said end 87 is upwardly bent and is pressed against the cover '18 its closed position. The end 87 thereby forms means limiting the upward movement of the latch under the action of the latch spring 84. llVhen the cover 18 is removed from the enclosure l1 the end 87 of the spring 86 is no longer restrained in position, and thereited inst downby tends to move upward because of its resiliency. Y

Due t0 the disposition of the flange 85 ot the latch above said end 87, the upward movement ot said end causes al movement of said` latch to disengage vthe roller 61 oi:

the switch mechanism, and thereby permits the switch members to move into open circuit position upon the removal ot the cover.

The overload protective means for the switch include the current coils 88, which are disposed above the supporting base 10 within the enclosure of casing 11. The movable element ot said coils are enclosed in the tubes 89, which project` through the lower portion 12 of the enclosure 11 and terminate in the time limit means 90, which are of common construction.

Pins 91 are centrallyl and movably disposed within the solenoids and at the top portion thereof and'project therethrough. Said pins are adapted t0 be engaged by the movable elements of said coils upon a predetermined current flow, and to be moved into engagement with a tripping frame, a component part @t which is disposed above said solenoids and pins.

Said tripping trame is formed of a flat strip portion 92 extending above said pins, and adapted to be engaged thereby under certain conditions of current flow, and the ends of said strips are bent at right angles 4to form arms 93, which are pivoted at 80 and 94: to the casing 11. One of said arms 98 is'disposed beneath the flange 85 of the latch 80, whereby in the upward movement ot .said tripping frame caused by the engagement therewith ot the pins 91, said arm will engage said flange 85 to move said latch, and thereby cause its. disengagement from the roller 61 of the switch operating mechanism, and thereby permit the movement of the movable switch member into open position- The under-voltage release means include a coil 95 which is secured in a housing 96, disposed beneath the enclosure 11. A pin or rod 97 is secured to the movable element of said coil and projects upwardly through the bottom 12 of the enclosure 11 and the base 10, and is formed with an enlarged end or head portion 98. The rod 99 is pivoted in supports 100 secured to the base 11, and is formed with an end portion 101, which extends substantially at right angles from said straight rod, and encircles the stem 97 of under-voltage release coil. The other end yportion 102 of said rod is bent in the reverse direction from the end 101, and a link 103 is pivoted thereto. link 103 is formed with a slot 104 at its upper end portion, and a pin 105 isdisposed therethrough and secured to the latch 80. The slot 104 ot said link provides means whereby the latch 80 may be moved independently ot said link to cause the opening ot the switch. The enlarged head 98 ot the rod 97, secured to the movable element ot the rio-voltage release coil, is normally maintained above and from contact with the end portion 101 of the'rod 99 due to the energizationotsaid coil.

the cneig-gization ot said coil is atv any time insuiiicient. to maintain the movable clement thereof in elevated position, said element will descend, due to gravity, and move the' enlarged head ot the rod 97, the-rect' into engagement with end portion 101 of the rod 99, thereby transmitting through said rod and the link 103, a blow sutlicient to move the latch 80 in an upward direction, and thereby cause the latch to becomedisengaged from the switch mechanism, which mechanism consequently is permitted to move vto open circuit position.

llhe locking means whereby the cover 18 locksv the oil receptacle 13 against unintentional removal. troin the switch housing, includes the vertical rod 106, which is slidably disposed in supports 107 secured to the enclosure or casing 11, and is normally pressed by a spring 108 against the cover 18. The. lower end oi said vertical rod is bent to form. an end portion 109, which projects through the supporting base 10 and enclosure bottom 1.2 into the path of movement ot one oii the screw portions 14, and thereby restrains said oil receptacle against detachment. f

l-Vhen thev cover 18 ot said enclosure 11 is removed, the rod 106 is no longer maintained in depressed position,fand therefore the rod moves'vertically upward under the action ot spring108, which movement withydraws the end portion 109 awayV 'from the patlroie movement ot a screw portion 111, and thereby permits the rotation of said oil receptacle tor detachment from the switch housing.

rl claim 1. ln an oil switch, an enclosing casing, an oil receptacle,'means removably securing said receptacle to said casing, a cover for said casing, and locking means controlled by said cover removably to lock said oil receptacle to said casing adapted to release the receptacle for subsequent removal trom the casing'.

i2. ln an `oil switch, an enclosing casing, kan oil receptacle removably secured thereto, a cover tor said casing, a locking pin movable by said cover into locking position with said receptacle and a spring engaging said pin to move it from locking position upon removal of the cover Jfrom the casing.

3. In an oil switch, an enclosing casing, an oil receptacle rotatably removably engagevable therewitln'a cover for said casing, and ai locking device normally held by said cover in a locking-position in which it prevents rotation of said oil receptacle having means to move it from locking position upon moving the cover from the casing.

4. In an oil switch, an enclosing cas-ing, an oil receptacle removably secured thereto, a removable cover for said casing, a loclring device for said oil receptacle normally held by said cover in locking position with said oil receptacle and means associated with said locking device arranged to move it from locking position upon the removal ot said cover, whereby said oil receptacle may be removed from said casing.

5. In an oil switch, an enclosing casing, an oil receptacle rotatably removably engageable therewith, a removable cover for said casing, a locking pin extended within said casing downwardly beneath said cover and engageable with said receptacle to prevent its removal, and a spring associated with said pin to withdraw it from engagement with said receptacle upon removal of said cover to permit the removal of the oil receptacle.

6. In an electric switch, a supporting plate, two spaced-apart supporting members secured to and4 depending from said plate, two bars of insulating material secured to said strips in spaced-apart relation, stationary switch members carried by one of said bars and movable switch members pivotally carried by said other bar.

7. In an electric switch, stationary and movable switch elements, an insulating bar to which said stationary switch elements are secured, a separate insulating bar to which said movable switch elements are secured, a frame to which said insulatingr bars are secured in spaced relation, a supporting base from which said frame depenf, s, said stationary switch elements comprising fiat strips -secured to its insulating bar having its lower end portions reflected to form contact facesq and its upper portions extended through said supporting base for eircuit connection, and switch operating mechanism supported above said base and extended therethrough for operative engage ment with the movable switch elements.

8. In an electric switch, a plurality ot stationary.7 and movable switch elements, a supporting base from which said switch elements depend, said movable switch elements comprising independent i'lat strips each formed with a reflected end portion, auxiliary contacts slidably arranged 'in said end portions, brushes arranged on said llat strips intermediate the length thereof for contact with the `stationary switch elements, the other end portions of said strips being twisted into a plane substantially at right angles to the plane of the body of the strip whereby said strips are pivotally connected to supports, a frame connecting said independent switch elements for unitary n'iovement and switch operating mechanism connected with the ends of Said connecting frame.

9. In an electric switch a stationary switch element, and a cooperating movable switch element comprising a ilat strip having its end portion re'lexed to form a rearwardly directed portion substantially parallel with the body oi' the strip and spaced therefrom, an auxiliary Contact slidably arranged .in said parallel end and body port-ions, a bruslr member carried by the body portion, and said other end portion twisted at substantially right angles to the body portion to form a pivotal connection with a support.

In testimony whereo'l I have signedy my name to this specification, in the presence of two subscribing witnesses.

GORDGN CAMERON Witnesses I-I. B. Davis, T. T. GimnNwoon. 

